1. State whether the given systems are stable,

marginally stable or unstable. Also explain why.

A) (D²+3D+2)D²y(t)=(D+3)x(t)

B) (D+3)y(t)=(D²+D+1)x(t)

C) (D²+D+1) (D²+D+1)y(t)=Dx(t)

D) (D²+5D+4)y(t)= (D²+D+1)x(t)

E) (D²-5D+4)y(t)= (D+5)x(t)